Calorimetric characterisation of the toxofilin-G-actin complex

In the present work, the thermodynamic characterisation of toxofilin-G-actin complex was completed with differential scanning calorimetry. The relative change in the under curve area of the un-complexed G-actin in the presence of varying toxofilin concentrations was used as an indirect indicator of the complex formation. The toxofilin could efficiently bind to G-actin with a K (D) value of 15.7 A mu M. Besides its binding activity, toxofilin stabilised the attached actin molecules as the T (m) value of G-actin increased to 64.19 A degrees C after the complex formation. Based on the findings, it is possible to conclude that even non-mammalian actin-binding proteins can efficiently modify the basic structural and dynamic properties of actin monomers.